Automatic telephone system



Oct. '2

l9 5 w. w. OWEN AUTOMATIC TELEPHONE SYSTEM EE E E E @EE EEEEEE E EEEE.EEEE E Oct. 6, 1925.

W. W. OWEN AUTOMATIC TELEPHONE SYSTEM Original F1 led Jane 13. sSheetsQ-Shqbt 2 Oct. 6,1925- W. W. OWEN AUTOMATIC TELEPHONE SYSTEM 3Sheets-Sheet 5 Original Filed June 12. 1918 Patented Oct. 6, 1925.

UNITED STATES PATENT OFFICE.

WILLIAM WALTER OWEN, 01 OAK PARK, ILLINOIS, ASSIGNOR TC AUTOMATIC'JELEC- TRIO COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

AUTOMATIC TELEPHONE SYSTEM.

Application filed June 12, 1918, Serial No. 239,504. Renewed July 19,1924.

To all whom, it may concern:

Be.it known that I, WILLIAM WALTER OWEN, a citizen of the United Statesof America, and a resident of Oak Park, in the county of Cook and Stateof Illinois, have invented certain new and useful Improvements inAutomatic-Telephone Systems, of which the following is a specification.

My invention relates in general to that type of telephone system inwhich connections are established between two subscribers automaticallyby the use of so called automatic switches without requiring theintervention of an operator.

More specifically my invention relates to certain improved switches oflarge capacity and methods of operating the same whereby the capacity ofan automatic system may be greatly increased and at the same time theoperations required of a subscriber are reduced to a minimum.

Among the objects of my invention is to provide in standard type ofStrowger switches such means as to enable said switches to have a muchgreater capacity so that the number of switches may be greatly reduced,thereby cutting down the initial cost of installation and whereby theselarge capacity switches may be controlled without requiring thesubscriber to operate his calling device as many times as 1n the past tosend the digitsof a called number and without requiring any materialchange in the mechanism of the automatic switches or of the callingdevice.

My invention is especially valuable in a private branch exchange oflarge capacity or in a large exchange of any other type. For instance ifit were desired to install an exchange of a mililon lines orthereaboutsthe subscribers directory numbers, in systems such as have beeninstalled in the past, would have so many digits or figures as to be avery serious drawback from the subscribers view point, and such anexchange would be quite costly in view of the large number of switchesrequired. In a system of the type which I have illustrated in thedrawings, however, it will be seen that a subscriber might call anyother subscriber in a 27000 line system with only three di its, in a810,000 line system with only our digits, and so on, said digits alsobeing a mixture of letters and figures which are much easier to rememberthan an all figure number.

In Fig. 1 of the drawings I have shown a layout or trunking diagram of asystem embodying my invention, showing only a portlon of a 27000 linesystem and the routes taken by calls from the various subscribers.Figures 2 and 3 show the switches used in such a system when aconnection is extended from a calling subscriber A (Figure 2) through aline switch C, a selector switch E, and a 900 line connector switch I-I(Fig. 3). I have shown all the apparatus in its normal position in thesedrawings. Fig. 4 shows the preferred form of calling device to be usedin my system. The calling device is of the well known type which sendsfrom one to ten impulses to the switches, depending upon the hole usedto rotate the dial. The only difference between this and the standardten impulse calling device is that the dial'instead of havin only oneset of finger holes, has three suc sets, each having the same relationto the operating or impulse sending mechanism: that is, if 1, Aror L areused only one impulse will be sent to the central exchange on the returnmovement of the dial, while it 3, C or N are used to operate the deviceonly three impulses will be sent in either case on the return movement.If however, any of the letters A to K are used to control the devicethen the springs 2 and 3 will be operated on e for any digit A--K toground one side of .the line circuit to in turn puli up a difi'erentialrelay at the exchange. If any digit L to X is dialed then the springs 4and 5 will be operated once to remove the short circuit from a highresistance 6 at the substation. These springs 2, 3, 4 and 5 it will beunderstood, may be mounted in any way or operated in any manner as ionas they close contact once on the fo'rwar movement of the dial beforethe regular digit is sent out by the return of the dial.

The mar inal and ditierential relays controlled by t ese two pairs ofsprings are associated with each switch which is used and are operatedto pick out a desired set of/line and rivate wipers in a large ca acityswitch whic carries a plurality of sec sets simultaneously to likepoints in banks associated with each wiper.

I have shown in the drawings only a line switch, a first selector, and aconnector, although it will readily be seen that the first selector maybe omitted or more selectors may be added without in any way departingfrom the spirit of my invention.

In the diagram in Fig. 1 I have shown a portion of a 27,000 line systemillustrating an application of the principles of my invention. I haveshown the first three 900 line groups of the first 9000 group across theupper part of the figure and the first three 900 line groups of thesecond 9000 group across the lower part of the figure. It will beunderstood that in such a system there will be arbitrarily three groupsof 9000 lines each, 10 groups of 900 lines each in each 9000 line group,and 6 groups of 150 lines each in each 900 line group. Each firstselector has access to 300 trunks, the first 100 or the lower bank ofeach selector leading to connectors in each 900 group of the first 9000;that is the first level of the first selector E leads to the tenconnectors H in the first 900 of the first 9000; the second level to tenconnectors in the second 900 of the same 9000 andso on. The second bankof this selector E leads to ten connectors in each ofthe ten 900 groupsof the second 9000, and the third bank leads to ten connectors in each900 group of the third9000. In the same manner a subscriber .D forinstance, in the second 900 of the second 9000 would also have accessthrough the selectors F with ten connectors H in each 900 groups of thefirst 9000, through the first bank of any selector F; with tenconnectors H in each 900 group of the second 9000 through the secondbank, and also with ten connectors in each 900 group of the 3rd 9000through the third bank. Each con-- nector has access to 9001ines andfor'the purpose of illustration. I have shown 60 connectors as havingtheir individual contacts multipled and leading to the 900 subscribersof one sub-group. The percentage may be varied according to traflicconditions.

I will now point out in detail the operation of my system when asubscriber such as A desires to call any other subscriber, referencebeing, had to the accompanying drawlugs. I I

When the subscriber at substation A sFig. 1) removes his receiver acircuit is c osed for the line relay 7 of the rotary line switch C (Fig.2). Relay 7 energizes to close a series circuit for relay "8 and magnet9, andalso closes a circuit from private wiper '12'direct to rotarymagnet 9. The switch now rotates astl is circuit meets grounded contactsof busy trunk lines to operate the magnet 9 and as soon as an idle wtrunk is reached, relay 8 being no longer short circuited by ground onwip'er 12 energizes in series with magnet 9 to disconnect the line ofsubstation A from the line relay 7 and connect said line to the linerelay 13 of selector E through wipers 10 and 11.

The circuit for line relay 13 extends from ground through the lowerwinding of relay 13, lower windin of the difi'erentlal relay 15, wiper11, to an through substation A, wiper10, upper winding of relay 15,marginal relay 14, and upper winding of relay 13 to battery. Relay 15does not energize over this circuit as the currents inits two windingsoppose each other. Relays 13 and 14, however, energize and'attract theirarmatures. Relay 13, upon energizing, closes a circuit for slow relay 16and opens one point in the circuit of release ma et 17. Relay 14 uponenergizing, has no e ect at this time except that it'opens one point inthe circuit of switching relay 18. Rela, 16 supplies a holding ground tothe re ay 8 of line switch C, and prepares a circuit for the verticalmagnet 20 and slow relay 21.

The subscriber at A may now operate his calling device to send the firstdigit of the called number. This digit may be any one of 30 clmracters,that is. it may be any figure from 1.0, any letter A-K or any letterL-W. If any figure (1-0) is dialed then neither of the relays 14 or 15will have any function and the line relay- 13 will be operated inaccordance with the number dialed (1 for instance) to step the wipers22-30 inclusive, to the first level of their respective banks. Asneither of the relays 14 or 15 have closed their respective circuits,and therefore relays 18 and 19 are not energized, then the trunk lineand the test conductor will be connected only to the wipers 22, 23 and24, respectively, the other wipers being open at the contacts of relays18 and 19.

It will be noticed that although relay 14 will deenergize at eachimpulse with the line relay, the circuit of the switching relay 18 willnot be closed as the said circuit extends from ground through springs31, springs 32 and 33, off normal springs 34, springs 35, and saidrelay, so that, in order to close said circuit, relay 14 must bedeenergized while the line relay is energized. If any letter A-K is usedfor the first digit, then, as the calling device is drawn down on theforward movement and the springs 2 and 3 are closed, a ground will besupplied to the line circuit which short circuits one winding of eachrelay 13 and 15. Relay 13 is not afi'ected by this operation but relay15 now attracts its .armature to close springs 36 and energize theswitching relay 19. Relay 19, upon energizing, locks itsellj energizedto the ground on relay 16, and connects the extended trunk associatedwith this outer row of holes will be operated momentarily to include there-' sistance 6 in the line circuit. This operation does not affect therelays 13 or 15 but causes the marginal relay 14 to fall back to closethe previously traced circuit of the relay 18. Relay 18 will thereforeenergize and in this case switch the trunk to the upper set of wipers28, 29 and 30, and lock itself to ground. As soon as the preliminaryswitching of wipers is completed and as the dial returns, the springs CDat the substation are interrupted in the usual manner to step all of thewipers to some level of their banks. Assuming that subscriber A desiresto call a subscriber A for instance, in the first 9000 group, then thefirst digit would be a figure and neither of the relays 18 or 19 wouldbe operated. The vertical magnet 20 operates to step the wipers to thedesired level and as soon as the impulses for this digit cease, relay 21falls back to close a circuit for rotary magnet 37 from ground'throughsprings 38, springs 39 and 40, springs 41. and magnet 37 to battery.Relay 42 was energized upon the initial energization of relay 21. As thetest conductor is connected only to wiper 24 which is one of the lowersets of wipers, then the switch in rotating will select an idle trunkline in its lower bank. As soon as an idletrunk is found the relay 43.which has heretofore been shorted in passing over busy trunks, energizesto disconnect the mags nets of switch E from-the trunk circuit to extendthe same to the line wipers 22 and 23 which are now resting upon an idletrunk line leading to an idle connector such as H (Figs. 1 and 3). Thisconnector is one of the ten which is accessible to subscribers of thefirst 150 of each 900 and which has access to 900 lines in the first9000 line group.

The connector H is of the well known Strowgertype of switch, being sideswitchless and having, instead of the usual pair of line and privatewipers. nine sets of line and private wipers, each being adapted tocon-. nect with any one of 100 lines. The subscriber must therefore selet one of the nine wipers to determine in which 900 his called line islocated and must then step the switch up and around to the desiredcontacts. All the wipers will of course move together but only thosewipers will be effective-which are selected by the combination ofletters or figures used in operating the calling device.

As the first digit was described as 1 the selector has elected the first900 group of the first 9000 and the connector H therefore must now beoperated to pick out the first set of line and private contacts in thefirst level of the lower bank of said connector. As in the case of theselector, the circuit for the line relay 45 includes also a marginalrelay 46, and a differential relay 47 which relays are controlled in thesame manner as the relays 14 and 15 of selector E. The first digit bein1 (in this case) relays 46 and 47 have no e ect and the trunk circuitthrough the connector remains connected to the wipers which have accessto the first 100 lines in the 900. As the impulse for this digit isdelivered to line-relay 45, said relay falls back to close a circuitfrom ground through springs 48, springs 49, relay 77, and verticalmagnet 78 to battery. Magnet 78 therefore operates in the manner usualto switches of this type to step all the wipers 50-76 inclusive, to thefirst level of their associated banks. Relay 77, upon energizing, closesthe springs 79 and 80 so that after the switch takes its first step andthe off normal springs close, the circuit of the vertical ma et passesfrom springs 49 through springs 81, and through springs 80 and 7 9 tosaid relay magnet. After the impulse or impulses of this first digitcease. relay 77 falls back and prepares a circuit for the relay 82 androtary magnet 83 at springs 80 and 84. The next digit being 1 the linerelay falls back to operate relay 82 and magnet 83 in the usual manner.Magnet 83 steps the wipers to the first contact in the selected leveland relay 82 connects the test relay 85 to the private wiper 52. Relay82 is slow to fall back so that if the called line is busy and a groundpresent on the private contact thereof then relay 85 will energize andlock itself to ground at springs of slow relay 86 before relay 82'fallsback. Relay 85 connects busy tone to the line circuit, and opens a pointin the circuit of relay 82 and magnet 83, whereupon the callingsubscriber may release thefconnection and call again. If the called lineis idle, however, relay 85 does not energize and as soon as relay 82falls back a circuit is closed for the upper winding of wiper cut onrelay 87 which extends from ground at springs of relay 86 throughsprings 88, upper winding of relay 87, springs 89, back contacts ofrelays 90, 91, 92 and 93, private wiper. 52, and through the bridge cutoff relay of the called line to battery. Relay 87 energizes to cut theline circuit of the called line through the springs 94 and 95', to theringing circuit R and to the usual rin cut oil' relay 96. As soon-as thecalled subscriber answers the relay 96 operates to disconnect theringing circuit from the called line and eonnect said line to thesubstation A and to the windings of the back bridge relay 97 whichsupplies said called line with talking current. Conversation may nowproceed in the usual manner and the connection will be released by thecalling subscriber in the usual manner.

Now should the subscriber have desired to call a subscriber whose lineis located in the second hundred of this 900 group then he will call11-A instead of 111. In this call the switches will be operated in themanner explained until the last digit, when A is dialled after theswitch has been operated vertically the relay 47 will be operated by theclosure of springs 2 and 3. The energizing of relay 47 will now close acircuit for the switching relay 93 from ground through springs 98, offnormal springs 99 and 100, and'relay 93 .to battery.

. Relay 93 locks itself to ground at springs of relay 86 and switchesthe trunk circuit from the wipers 50, 51 and 52 to the wipers 53, 54 and55 which have access to the second hundred or second bank.

Should the desired subscribers line be located in the third hundred thenthe called number Would be 1--1L, that is, just before the last digit,the relay 92 would be operated by the springs 4 and 5 through the mediumof marginal relay 46 and springs 102, 104 and 103 to switch the trunkcircuit to the wipers 53, 54 and 55 which have access to said thirdhundred.

. Should the called line be in the fourth hundred the called numberwould be 1A1. In this case just before the second digit the springs 2and 3 wouldbe operated to energize relay 47, and relay 47 closes acircuit' for switching relay 91 through springs 98, 99 and 101, so thatthe trunk is switched to wipers 59, 60 and 61. If the call line is inthe fifth hundred then the called number would be 1AA. In this casesprings 2 and 3 will be closed just before the second digit to operaterelay 91 through springs 98, 99, and 101, and said springs will again beoperated just before the last digit to cause relay 47 to close thecircuit of relay 93, through springs 98, 99 and 100. The trunk circuitwill be switched in this case to wipers 62, 63 and 64 through frontcontacts 106 and 107 of relay 91 and through front contacts 107 and 108of relay 93. Should the called line he in the sixth hundred the callednumber would be 1A-L. In this case springs 2 and 3 will operate relay 47before the second digit to energize relay 91 through springs 98, 99 and.101, and the springs4 and 5 will operate relay 46 just before the lastdigit to energize relay 92 through Springs 102, 104 and 103. The trunkcircuit will therefore be connected through front contacts 106 and 107of relay 91 and through front contacts 109 and 110 of relay 92 to wipers65, 66, and 67.

Should the called line be in the seventh hundred then the called numberwould be 1-L-1 and in this case springs 4 and 5 will be closed justbefore the second digit to cause relay 46 to energize relay 90 throughtrunk through front contacts 111 and 112 of ".rlay 90 to wipers 68, 69and 70.

Should the called line he in the eighth hundred, then the called numberwill be 1-LA and in this case springs 4 and 5 through springs 98, 99 and100, thus con-- necting the trunk through front contacts 111 and 112 ofrelays 90'and front contacts 113 and 114 of relay 93 to wipers 71, 72and 73. Should the called line be located in the ninth hundred then thecalled number would be 1LL, and in this case the springs 4 and 5 wouldbe closed before the second digit to cause relay 46 to energize relay 90through springs 102. 104 and 105 and again just before the last digit tocause relay 46 to energize relay 92 through springs 102, 104 and 103,thus connecting the trunk circuit through front contacts 111 and 112 ofrelay 90 and front contacts 115 and 116 of relay 92 to the'uppcr set ofwipers 74, 7 5 and 76.

Thus it will be seen that the order of letters and figures in the callednumber determines the group of the called line, while the particularletter or figure used determines the line in the group.

It will be understood that in any of the above cases, although I havestated for instance, that to call into the 6th group the digit would be1AL, yet it will be understood that there are 100 combinations whichwill select the same sixth set of wipers, that is 1AM to W, 1A to BM,and up to OKW, depending upon the location of the called line in thatgroup, and also in the first group the number may be 111, 112, 113, 121,122, etc.

All of the calls whichI have so far described arein the first 9000lines, and any line may make such a call by using any connector H,H,'etc., of the first 9000. Now should the calling subscriber desire tocall a subscriber in the second 9000, then the first digit will alwaysbe one of the letters A to K, and in this case the selector E will beoperated as explained, that is, whenever the first digit of a number isany of the lettors-A to K, inclusive, the springs 2 and 3 at-the callingdevice will be operated to cause relay 15 of 'the selector to energizethe" switching relay 1'9 which in turn connects the line circuit to theline wipers 25 and 26 and the test conductor to the private wiper 27instead ofto wiper 24. In this case of course,vthe switch afterselecting a level in the second 1000 group or in the second bank of theselector Wlll rotate to automatically select an idle trunk line in thesaid level or an idle one of ten connectors which have access to acertain 900 group in said second thousand. In the same manner it thecalled number is located in the third thousand then the first digit ofthe called number will always be one of the letters L the line circuitand a trunk leading to connectors in the third 0000 will be selected.

It will" therefore be seen that the systenr is divided first into threelarge groups of 9000 lines, which may be designated as the 1, A andLgroups, and that each 9000 group is divided into ten sub-groupsof 900lines each, the particular 900 group in the selected 9000 groupdepending upon which one of the numbers or figures in a series are used;the 900 groups are further divided into subgroups of 100 lines each, andthe sub-group selected depends upon the order inwhichthe zones or rowson the "calling device are used for the last two digits. This selectionand distribution it'is thoughtis new and constitutes' a very greatadvance in the artas it practicall enables a subscriber to send fivedigits 0 a called number or more, with only three operations of thecall'in and reduces the number of switc es materially.

Having fully described and ascertained the features of my invention whatI consider to be newand desire to have rotected by Let ters Patent willbe pointed out in the appended claims,

What I claim is:

1. In a telephone system, an automatic switch, a, plurality of sets ofwipers for said switch a second plurality of sets of wipers for theswitch, a calling device for controlling said switch to extend aconnection over an of said sets of wipers in accordance wit two of thedigits of a called number, meanscontrolled by said calling device forautomatically selecting one set of said first plurality of sets ofwipers before theswitch is operated in response to one digit, and meansfor automatically selecting one of said second lurality of sets ofwipers before the itc is operated in response to another digit.

In atelephone sstem, an automatic switch, a plurality 0 sets of wipersfor, said switch, a callin device for controlling said switch to eaten aconnection over any of said sets of wipers in accordance with two of thedigits of a called number, means controlled by said calling device torautomati cally selecting one of a pair oi said sets of r wipers beforethe switch is operated in response to one digit, means for automatically selecting one of another pair of said sets of wipers before theswitch is operated inresponse to another di t, and automatic meanscontrolled both he ore and after the switch is operated in response tothe first digit for automatically selecting another of wipers 3, in atelephone ,ystem, an automatic device switch, a plurality of wipers forsaid switch, a calling device for controlling said switch to extend aconnection over any of said wipers in accordance with two of the digitsof a called number, means controlled by said calling device forautomaticallyselecting one of a pair of said wipers before the switch isoperated in response to one digit, meansfor automatically selecting oneof another pair of said.\vipers, before the switchis operated inresponse to another di'it, and automatic means controlled both beioreand after the switch is operated in response to the first di it forautomatically selecting one of a thir pair of wipers.

4. In a telephonesystem, an automatic switch, a plurality of wipers forsaid switch, a calling device, a plurality of rows of finger holes for,controlling said calling device to operate said switch, means associatedwith one of said rows of finger holes for causing said switch to extenda connection over one of said. wipers, means associated with another ofsaid rows of fin 2 holes for causing said switch to eaten a connectionover a difierent one of said. wipers, the wiper depending upon the rowused, said means also for extending connections over others of saidwipers when the calling device is controlled through the medium of morethan one of said rows to operate the switch.

5. In. a telephone system, an automatic itch, a lurality of, wipers forsaid switch, a ca mg device, a luralit of rows of finger holes for.control ing said calling 4 vdevice to operate said switch, meansassociated with one of said rows of finger-holes for causing'said switchto extend a connec-i tion over one of; said wipers, means associated.with another of said rowsot finger holes. for causing said switch, toextend a connection. overa' difierent one of said wipers, the wiperdependingnpon the row used, and ineans ior extending connect-ions overothers of sa d-wipers when the calling device is controlled throughthe-medium oi more than one of said rows to operate the switch, thewiperused in the latter case depending upon "the order in which the rowsor holes werensed to operate the dial.

'5. in a telephone system, an automatic switch, a line leading to saidswitnh, a

plurality oft" wipers for said switch, a raiit'y oat relays for saidswitch, a caliin device for controlling said switch to eateneconnections, automatically controlled means in said switch forenergizing only one of relays before the is operated or for energizingeither of two other oi said relays after the switch is partially op-=erated, means contnolled by each relay for connectio ine to differentone of said 1.2

N. k W 2 a In a controlled hy we a W I necting said has to differentones of said line, an automatic'switch accessible to said .and then in"a rotary direction, a pluarlit of wipers for said switch, a plurality ofre ays 1-,

kinda calling device for said line for operating said switch firstin avertical direction for said switch, means controlled by the ca ingdevice for operating one of said relays before the switch is operatedvertically. to switch said line to'one of saidwipers, and meansfor-operating another of said relays after the vertical movement of theswitch to switch the line to another of said wipers.

8. In a telephone system, a subscribers line, an automatic switchaccessible to said line, a calling device for said line for operatingsaid switch first ina vertical direction and then in a rotarydirection,.a' plurality of wipers for said switch, a plurality of relaysfor said switch, means controlled by the calling device for operatingone of said relays before the switch is operated verticallyto switchsaid lineto one of said wipers,

means for operating said relay after the ver-' tical movement of theswitch to switch the line to another of said wipers, said means also foroperating one-relay before the vertical movement of the switch andanother relay after the vertical movement of the I switch to connect theline to another of said wipers.

9. In a telephone system, a'subscribers line, an automatic switch forsaid line,

means on the line for operating said switch in a' vertical and then in arotary direction,

a lurality of wipers for the sw1tch,,a plu- "ra ity of relays for theswitch, means for 40 X operating one of said relays before the verticalmovement of the switch to connect the line to one of said wipers, andmeans for operating "another of saidrelays after the vertical motion toconnect the line to another of said wipers.

10. In a telephone system, a subscribers line, an automatic switch forsaid line,

wipers,

means on the line for operating said switch in a vertical and then in arotary direction,-

a lurality of wipers for the switch, a plu ra ity of relays for theswitch, means for o crating one of said relays before the verticalmovement of the switch to connect the line to one of said wipers,said'mea'ns for operating said one relav after the vertical motiontojconnect the line to another of said and means for operating anotherof said-,relays to switch the line to another of said wipers.

11. In a telephone system, a subscribers line. an automatic switch forsaid line. means on the line for operating said switch in a vertical andthen in a rotary direction. a"

plnralit of wipers for the switch. a plurality of relays for the switchmeans for opdepending erating one ofsaid relays before the verticalmovement of the switch to connect the line to.

one of said wipers, said means for-operating .said one relay after thevertical motion to connect the line to another of said wipers, means foroperating another of saidrelays before the vertical movement of theswitch to connect the line'to anotherwiper, and for operating said relayafter the vertical movement of the-switchto connect the line to anotherwiper. Y

12. Ina telephones stem, a subscribers line, an automatic switc forsaid-line, means on the. line for operating the switch ina vertical andthen in. a rotary direction, a fplura'lit of wipers for the switch, apair of relays or the switclnmeans for operating either of said relayseither before or after.

the vertical operation of the switch, and

means controlled by either relay for connecting the line to a differentone of said wipers upon the relay energized and whether. it is energizedbefore or after the vertical movement of the switch.

13. In a telephone system, axsubscribers line, an'automatic switch forsaid line, means on the line for operating the switch in a vertical andthen in a rotary direction, a

er it is energized before or after the vertical,

movement of the switch, and. means controlled by said relays forswitching the line to others of said wipers when-either relay isenergized both before and after the vertical movement. 1 v

1 In a telephone system, a subscribers line,an automatic switc forsaidline, means on the line foroperating the switch in. a vertical andthen ina rotary direction, a

pluralit oflwipers for the switch, a pair of relays or'the switch, means'for operating either of said relays either before or after thevertical operation of. the switch, means. controlled b either relay forconnecting the line to a di erentone of said wipers de ending upon-therelay energized and whet er it is energized before or after the verticalmovement of the switch, and means controlled by said relays forswitching the line to others of said wipers when either rela isenergized both before and after thevertical movement, the wiper selecteddepending P0121 theorder inw ich said relays are enerize g 15. In atelephone system, a subscribers line, an automatic switch for said line,a pluralit of wipersfor said switch, means on the line for moving saidwipers in a vertical and then in a rotary directiomautomatic no a meansfor grounding said line before the vertical movement of the switch toconnect the line to one of said wipers, and for including a resistancein the line after the cal and then in a rotary direction, automaticmeans for grounding said line before the vertical movement of the switchto connect the line to one of said wipers, and for grounding the lineafter the vertical movement to connect the line to another of saidwipe-rs, and automatic means for including a resistance in said line toconnect the line to another wiper.

17. In a telephone system, a subscribers line, an automatic switch forsaid line, a plurality of wipers for said switch, means on the line formoving said wipers in a vertical and then in a rotary direct-ion, meansautomatically controlled by said first means for grounding said lineeither before or after the vertical movement or for including aresistance in said line either before or after the vertical movement,and means for switching the line to a certain one of said wipersdependent upon the time the line is so controlled.

18. In a telephone system, a subscribers line, an automatic switch forsaid line, a plurality of wipers for the switch, means on the line foroperating'the switch to move said wipers in a vertical and then in arotary direction, means for' grounding the line before the verticalmovement of the switch to connect the line to one of said wipers, or forgrounding the line after the vertical movement to switch to a second ofsaid wipers, means for including a resistance in the line before thevertical movementv to connect the line to a third wiper, or forincluding said resistance after the vertical movement to connect theline to a fourth wiper.

19. In a telephone system, a subscribers line, an automatic switch forsaid line, a plurality of wipers for the switch, means on the line foroperating the switch to move said wipers in a vertlcal and then in arotary direction, means for grounding the line before the verticalmovement of the switch to connect the line to one of said wipers, or forgrounding the line after the vertical movement to switch a second ofsaid wipers, means for including a resistance in the line before thevertical movement to connect the line to a third wiper, or for includingsaid resistance after the vertical movement to connect the line to afourth wiper, and-means for switching the line to others of said wipersby grounding the line both before and after the vertical movement orincluding the resistance both before and after.

20. 'In a telephone system, a subscribers line, an automatic switch forsaid line, a plurality of wipers for the switch, means on the line foroperating the switch to move said wipers in a vertical and then in arotary direction, means for grounding the line before the verticalmovement of the switch to connect the line to one of said wipers, or forgrounding the line after the vertical movement to switch to a second ofsaid wipers, means for including a resistance in the line before thevertical movement to connect the line to a third wiper or for includingsaid resistance after the vertical movement to connect the line to afourth wiper, and means for switching the line to others of said wipersby grounding the line both before and after the vertical movement orincluding the resistance both before and after, or by'grounding the linebefore the vertical movement and in ing the resistance after saidmovement. a

21. In a telephone trun ng system, lines divided into groups andsub-groups, said subroups being further divided into smal er groups, acalling device for each line having three rows of finger holes forcontrolling the same, means controlled by the operation of the device--f the first digit of a called number for W ecting one of a pluralityof main groups, a sub-group in the main group and an idle trunk leadingto that sub-group, means controlled by the operation of the device forthe second and third digits of a called number for selecting a secondsub-group in" the selected sub-group, a sub-group in the second selectedsub-group, and a line in the third selected sub-group.

22. In a telephone trunking system, lines divided into groups andsub-groups, said sub-groups being further divided into smaller groups, acalling device for each line having three rows of finger holes forcontrolling the same, means controlled by the operation of the 'devicefor the first digit of a called number for selecting one of a pluralityof main groups, a sub-group in the main group and an' idle trunk leadingto that sub-group, means controlled by the operation of the device forthe second and third digits of a called number for selecting a secondsub-group in the sellected sub-group, a sub-group in the second wipers,lines accessible to each wiper, means for operating said SWltOh inresponse to two digits of a called number to extend a con-.

nection over one of said wipers to :1. called one of said lines, aplurality of relays for switching the calling line into connection withany of said wipers, an of said rela s operable automatically eit erbefore t e first of said digits or after the-first one of said digits. i

24. In a telephone stem, a callin line, a switch for said line aving aplurafity of grou s of lines accessible thereto, wipers for t e switch,means operated in response to impulses corresponding to digits of acalled number for moving said wipers to extend a connection, andautomatic means operated independent of any movement of the wipers fordetermining the group of lines into which the call is to be extended,

said group selecting mechanism consisting of a pair of relays each 0erable either before or after the first of said digits.

25. In a telephone system, an automatic switch, a line leading to saidswitch, a plurality of wipers for said switch, a plurality of relays forsaid switch, a calling device for controlling said switch to extendconnections, automatic means in the switch for energizing one of saidrelays after the switch is seized or for energizing certain pairs ofsaid relays, each relay having means for connecting the line to adifferent one of said wi ers, and means controlled by the energizatlonof any pair for connecting the line to a difi'erent one of said W1 ers,

igned by me at Chicago, Cook County,

